Power and value assignment puzzle

Substitute each capital letter in bold by a different digit from 0 to 9, such that (TAU).BETA when rounded off to the nearest integer is equal to PI, and the absolute difference of (TAU).BETA and PI is the minimum. Each of T, B and P is nonzero.

Substitute each capital letter in bold by a different digit from 0 to 9, such that (TAU).BETAwhen rounded off to the nearest integer is equal to PI, and the absolute difference of (TAU).BETA and PI is the minimum. Each of T, B and P is nonzero.

I underlined a little of your post there...
Do you mean PI as in π, the ratio of a circle's circumference to it's diameter?